The application relates to devices and methods for delivering, administering, dispensing or injection a substance. More particularly, it relates to an apparatus for injecting an active substance having an injection needle, a housing, a receptacle for the active substance, an injection piston that is displaceable in the receptacle for the purpose of expelling the active agent, and a needle protecting device that is displaceable relative to the housing.
A task of needle protecting or covering device is to protect persons from unintentional injury by an injection needle after the use of an injection apparatus. An advantage of such devices is also that the patient is spared a view of the injection needle, which is felt as unpleasant by many people. Needle protecting devices, caps or covers are known in many forms, both in connection with manually operated syringes and with so-called autoinjectors.
For example, the document WO09714455 describes an autoinjector having a needle protecting sleeve that is displaceable in a housing, including a sleeve which during the injection rests against the skin of the patient and is prestressed by a spring such that, upon retraction of the autoinjector, the needle protecting sleeve is pushed forward relative to the autoinjector and covers the injection needle. Locking means operative between the needle protecting sleeve and the housing ensure that the needle protecting sleeve cannot be pushed back again and, thus, that no unintentional injury by the injection needle can occur. Means for canceling or releasing the locking are not disclosed.